In order to improve the high speed performance of a radial tire, proposals have heretofore been made on tires having a folded belt structure in which both ends of a belt layer of a tire are folded back towards the tread side to form a belt portion, e.g., belt structures as shown in FIGS. 2, 3, and 4 which are typical cross-sectional view thereof.
However, tires having these folded belt structures are poor in balance in respect of high speed performance and durability, driving stability, and riding comfort and are disadvantageously large in ply steer, which makes it difficult to control the steering wheel.